1. Field of the Invention
The present invention relates to a magnetic recording medium. More particularly, it relates to a magnetic recording medium superior in durability.
2. Discussion of the Related Art
A magnetic recording medium is usually produced by coating a substrate, such as polyester film, with a magnetic paint composed of magnetic powder, binder resin, organic solvent, and other components. In the case of the floppy disk among the magnetic recording media, the magnetic layer is required to have good durability with a minimum of wear, because the magnetic layer of the floppy disk rubs against the magnetic head and jacket liner at the time of recording and reproducing.
One means commonly practiced to improve the wear resistance of the magnetic layer is to incorporate a lubricant into the magnetic layer. Examples of such a lubricant include fatty acids, oleyl oleate, butoxide stearate, fatty acid amides, liquid paraffin, and wax. These lubricants, however, are not necessarily satisfactory in their performance. For example, oleyl oleate and butoxide stearate do not improve the durability of the medium satisfactorily. Fatty acids such as stearic acid and oleic acid and hydrocarbon lubricants such as liquid paraffin effectively improve the durability but are poor in miscibility with the binder. When used in a large amount, they bleed out from the surface of the magnetic layer to stain the magnetic head.